Electric furnace for the treatment oe comminuted carbonaceous



BEST AVAILABLE COPX OMMINUTED IKE AND THB L 1923 AUGLE TREATMENT OF C AL 2l ELECTRIC FUR CARB ' Sept. 28 1926.

Patented Sept. 28, 1926.

UNITED STATES BEST-AVAILABLE conl PATENT OFFICE.

ELECTRIC FURNACE FOR THE TREATDET OF COMMINUTED CARBONCEOUS MATERIAL AlD THE LIKE.

Application filed April 21, 1923, Serial No. 633,644. Renewed October 22, 1925.

My present invention relates to electric furnaces, particularly, but not exclusively, such as are intended for the treatment of comminuted material, especially comminuted carbonaceous material, and aims to devise structures of the gene-ral character designated above Which'shall be simple in construction, and which shall have few parts and shall, therefore, be quite economical to manufacture and to assemble. Another; object of the present invention is to devise structures of the character specilied above which shall be certain and dependable in operation; which shall require little power for mechanical and heat generating purposes; which maybe readily assembled andas. readily disassembled for repair or'other purposes which shall make ampleprovision for the proper feeding of thematerial into, within and through the furnace during its treatment therein; which shall also make @adequate provision for the proper and eiicient stirring and mixing of the material during its treatment; which shall provide proper current distribution through thematerial for the heating treatment; and which v shall be capable of continuous, as distinguishedV from batch, operation. l f

A further object of the present invention is to devise furnaces of the generalfcharac'. ter specified above which shall permit the substantially continuous production of products of a highdegree of purity. In particular, ifvcomminuted carbona'ceous material, such as comminuted carbonized lignin residues, derived from the cooking liquors obtained from the treatment of Wood by the alkali (soda) process for the production of wood pulp, is treated in a furnace of the character designated above for the preparation of highly activated decolorizing carbons, the result is a 'remarkably pure decolorizing carbon characterized by a. high degree of purity and high electrical conductivity, corresponding to avery high degree of activation and decolorizing power.

In the accompanying specification I shall describe, and in the annexed drawing show, an illustrative embodiment of the device of the present invention. It is, however, to be clearly understood that mv invention is not limited to the specific embodiment thereof herein shown and described for purpose.: of illustration only.

Referring to the drawing, wherein I have shown the aforesaid illustrative embodiment of the present invention:

Fig. 1 is a side elevation, partly broken away, of the furnace comprising the aforesaid illustrative embodiment;

Fig. 2 is across sectional view of the same'talren along line 2 2 of Fig. 1 of the drawing,

Fig. 3 is a fragmentary longitudinal sectional viciv of the casing and associated electrodes Fig. 4 is a side view, and

Fig. 5 is an end View, of the central shaft and associated electrodes.

Referring now to the aforesaid illustrative embodiment of the present invention, and more particularly to the drawing illustrating the same, the furnace comprising said illustrative embodiment includes a casing 10, Which is preferably of substantially cylindrical form. W'hile the casing 10 may be made of various materials, I prefer that the saine shall comprise an outer shell 1l of metal, such as iron or steel, provided with i an inner lining l2-of some heat insulating and electrically non-conducting material, such as the fire brick 13.

Mounted on the inner face 14 of the casing are a plurality of combined feeding means and outer electrodes which may have any desired form, but are preferably in the form of a series of conveyor vanes or blades 20. The varies or blades 20 preferably comprise a plurality of series of spiral elements, nine such longitudinally disposed lseries being shown in the specific embodiment herein described for purposes of illustration only. Preferably, the successive series of conveyor vanes or blades 2O are staggered with respect to each other, as more clearly shown in Fig. 3 of the drawing.

Suitably mounted within the casing 10 is a shaft carrying a plurality of combined stirring rods and electrodes in the formof rods 3l. The rods 31 are arranged on the shaft 30 in pairs, the rods of each pair being preferably diametrically oppositely dispoised. Successive pairs of rods, however, as more clearly shown in Fig. Il of the drawing. are angularly disposed with relation to cach other. This arrangement, I have found, is very suitable for effecting the proper stirring of the charge Within the furnace, and for bringing about a proper distribution; off current through. the mass of materialbeing treated in the furnace.

Suitable means are provided for effecting a relative movement, such. as -a rela-tive rotation, of the inner shaft 30, carrying the inner electrodesSI, with respect' :to the casing l() carrying:T on the inner surface 14 the-reot` the outer electrodes 20. For this purpose I mayrotate either the casing 10,'

carrying the :outer electrodes 2O on-the inner surface 14 thereof, or .the inner shaft 30, carryingl the inner electrodes 3L Or else, I may, as more clearlysliownin Fig. l of the drawingrotateboth sets otelectrodes relatively to each other, eitl,ier .inA the same directionat diterent angular rates of.rotation, or, and preferably, inI OPPOSitedirections at predetermined angular speeds ofrotation.

While vari ons, means maybe employed for this purpose, I pref-'er to use the means shown in Figs. l and Q 'of the drawing, and comprising a plurality of bearing bands 40 and 4l surrounding the'outer .ivallfof rthe casing la'nd'bearing on: a vpluralityet` sets of cylindrical roller bearings 4Q- and 4 3, respec tively; bearing boxes 44 and 45, 'resp:eiti'velyf lso mounted .on -the outer periphery' ofthe casing 10 is afgear' wheel 46 meshing with a pinion 47 carried by a shaft- 48,'Which borne astandard'4`9l The- "shaflf 48.1is driven from any suitable sourcejof 'powe-r, diagrammatically sljioiy'nfr in theidrawing' 'Y and ,A indicated by reference'cha'ractrtl, i'

The'shaft 3Q carrying" the electrodes 31 is likewise rotated," Forthispurpose, I pro- -vide Athe' charge' or'feed'fhopp'e'r 60, having the feed inlet 61 ,andth'e flanged collar.62, Within which", thesliell '.10 V.may freely rotate, with an integrall'exten'sion 63 inthe forni of ahsleevehthrough 'whichlth'e end 32 of the sha-ft 30 passes. 'At 'itsuter extremity, the end'32 of the shaft 30 car ries'a spira-l gear 64 l meshingwitlra worm gear 65 carried by a shaft 66`1 which also carries a pulley 6T operated by a belt 68Inounted on a drive pulley 69 operated from, anysuitable Vsource of power, not here deemed necessary to be shown; The other extremity 33 of the shaft 30 passes through an extension Oon thedischarge hopper 7l which is provided, as at 72, with a bearing permitting the'free rotation of tfhecasing I0 within the same and with the discharge outlet 73 at its lower end.

' In-.orderto' provide current conducting means forthe sets ot'- electrodes 20 and 3l, I provide the .end 33 ofthe shaft 30 with aconductor -ring or sleeve 8O contacting witlrav-brush- 8lv leading, by means of the wireorconnector 82,-to one of the pol-es, suchas'the'positive pole, of'any suitable source 'of ,current:supply-, not here deemed neCessaryto-be shoWnl Inthis-way connection is made'witlrthe-shatt() and with the electrodes 31- carriedl fthereby. The casing l0 carries a conductor ring orsleeveSS disposed about the periphery'of the casing, this rlng contacting with a brush S4 connecting,

by' means of the Wire or connector 85, with the negative pole of the source of current supply already referredto. By any suitable connection means, generally indicated by reference character S6, theconductor ring 83 may be readily connected with some or all ofthe outer electrodes 20.

The manner of assembling!v the machine described above is substantially clear from the foregoing?r description. The ina-nner of operatingT the machine is also substantiall Y clear from the foregoing descriptionH-and maybe briefly summarized as follbws: Assuming that the material treated in thelffurnace, for'ythe purposes of illustration, is the comminuted lcarbonized lgnin residues Aalready referred to, and assuming,r thatthe machine is used to carry out the process described and elaimedin one oft' myncopendin applications bearing Serial No. 633,640, tile of even date liere\vith', in the preparationpo the material describedv and claimed Ointanotber of my cop'ending applications .bearing Serial No. 633,641, also filed of evendate lieren'ith,. the raiv material, generally .indicated by reference character M, is continui ously f ed into the machine `through the hopper 60 and thus enters theV heating chamber generally designated by reference character 10., where is' brought into operative' contact with the cooperating sets of electrodes v 2O and 31.

The electrodes 3l, by the continuous'rotation ot the shaft 30 onwhich the same are carried, are brought into intimate contact with the material Wit-hin the furnace and serre to thoroughlyjnix and stir'the same. The spiral feeding members 20, some or all of which may serve as electrodes by being connected' with the connection means 86, servev at the same time, by' reason ot' the continuons rotation of the casing 10 on the inner surface of which qthe membersl 20 are carried, to continuously feed `the material M Within the furnace forward during the heating operation from the feed hopper 60 towards the discharging hopper 71; The electrodes 20 and '3l being connected as above described, current of the desired density Will pass through thematerialiM Withinvthe furnace. i

In this Way the material'IM will be heated to the desired degree. The degreeof heat will, of course, depend upon the particular material being treated Within the furnace and the characteristics of the end product desired to be produced. rfhel heat should, in genera-l, be sufficient to volatilize the volatile substances present in the charge et the material, and to fuse the fusiblei mineral substances present in such material to the condition ot' small aggregates or cli'nkers llO Which adhere tothe electrodes and 31, and also to the inner Wall lat of the casing 10 carrying the electrodes 20, as Well as to the shaft carrying the electrodes 31. In this ivay the volatile and fusible substances referred to are removed from the charge as it passes progressively and continuously from the inlet toivards the outlet end of the furnace.

The folloiving is an example of an average analysis of average sample of ycomminuted carbonized lignin residues, such as may be treated to remarkable advantage in the furnace described above:

`Analyss of comm/mired carlionz'zccl lig/nin The resulting product is of greater purity and of very high conductivity, corresponding to a high degree of activation and decolorizing poiver. An average analysis of the resulting product is substantially as follows:

Analysis of final product.

Carbon 97.60 Ash 2.40

Analysis of aslz..

Calcium 0.16 Sodium, Naz() 0. Magnesium, Mg() 0.16 Chlorides, (C12) 0. 06 Sulphates (SOB) 0.78 Silica, Si@2 0. 50 Iron and alumina (FegO, i\ l2O) 0. 39

The time of treatmentwill, of course, depend upon the particular material being treated, but in general is about 15 to G0 minutes. The conductivity of the final product may be as great as five times that of the raw material initially admitted to the machine. rEhe product also possesses a high degree of neutrality, Which'is very desirable, and possesses a decolorizing povver substantially, and often as much as 20 per eEsT AvAfLAetE com cent, greater than the best activated carbous hitherto produced.

From the foregoing description it ivill be noted that the machine is simple in construction, possesses comparatively feiv parts, and is capable of very economical and convenient fabrication, assembly and operation. In operation, the machine is certain and dependable, requiring a minimum of poiver for mechanical and heating purposes. The yoperative parts of the machine. particularly the electrodes, may be readily installed and as readily removed for cleaning, repair or re placement- The machine is so constructed and arranged as to provide for the proper feeding and mixing of the material Within the furnace during its treatment therein, as Well as proper distribution of the heating current through such material, being atthe same time capable of producing a high grade of material under yconditions permitting aV very hieh yield, considering the amount of raiv material and current employed, all of these desirable results being accomplished With a minimum amount of equipment, power, labor and material.

It may here be stated that the carbonized iignin residues referred to herein are the residues remaining after leaching the residues obtained by carbonizing the spent or used cooking liquors derived in the treatment of Wood by the al rali (soda) process in the production of Wood pulp; and that the terms activation and decolorizing, or their equivalents. as used in the specific tion and claims, include also deodorization, purification and filtration.

llfhat I claim as my invention is:

1. In an electric furnace for the treatment of comminuted carbonaceous or like material, a heating chamber, a. plurality of outer electrodes disposed in the outer portions of the space Within said heating chamber, a. plurality of inner electrodes disposed ivithin said outer electrodes, and means for moving both the outer and inner electrodes. l

2. In an electric furnace for the treatment of comminuted carbonaceous or like material, a heating chamber, a plurality of outer electrodes disposed in the outer portions of the space Within said heating chamber, a plurality of inner electrodes disposed Within said outer electrodes, and means for movingl both the outer and inner electrodes, one of said sets of electrodes being formed to advance the comminuterL material during the relative movement of said tivo sets of electrodes.

3. In an electric furnace for the treatment of comminuted carbonaceous or like material, a heating chamber, a plurality of outer electrodes disposed in the outer poi'- tions of the space Within said heating chan:- ber, a plurality of inner electrodes` disposed llO Within said p efectingV relative movement of said outer and inner electrodes, the electrodes of said set of Vouter electrodes being. in the form ofV spiral elements for advancing. the commi# nuted material during the relativel movementof said two sets of electrodes 4l. An electric furnace for the treatmentboth outer? and inner electrodes relative to each other. p

5.. An electric furnace for the treatment of? comm-inuted carbonaceous material and the like, comprising a1 substantially cylindrie-al container, a plurality of outer electrodes carried by'said container adjacent the inner Wall of the same, a plurality of inner electrodes disnosedr'within said outer 'electrodes, and. means for rotating said containerv and the outer electrodes carried thereby, said electrodes being adapted to advancev the material through the furnace upon rotation thereof L Y 6I: An. electric"furna`ce' for the treatment of comminuted carbonaceous material and the like, comprising a container, a pluralityT ofy outer electrodescarried by said 'container adjacent the inner Wall of the same, a' plurality of yinner 'electrodes disposed Within said outer electrodes, and means for effectu ing a relative movement of said outer and inner electrodes, the electrodes of said set of outer electrodes being in the form ot spiral elements'for advancing thel comminuted material during the 4relative movement of'said two'sets of' electrodes. r

7. An electric furnace forthe treatment of comminuted carbonaceous material and the like, comprisinga substantially cylindrical container, aplurality of outer elec trodes carried Aby said container'adja'cent the inner Wall of the same, a plurality o5 inner electrodes disposed Within said 'outer electrodes, and means for rotating said container and the outer electrodes carried thereby to thus. effect arelative movement of sain outer and inner electrodes, one'of said sets `of' electrodes-being formed'to ad Vance the'comminuted material during .the relative movement of said-two sets of elecy trodesfV 8.A Anelectric .furnace for the treatment of comminuted carbonaceous material and the like, comprising a substantially cylindrical container', a `plurality of outerV electrodes carried by said container adjacent the inner4 Wall Vof the same, a plurality of inner electrodes disposed Within said outer Velectrodes, and means forV rotating said container and the outer electrodes carried igeonaaa outer electrodes, andmeans foressi" Avaitasts com thereby to thus effect a relative movement of said outer and innerk electrodes, the electrodes of said set of outer electrodes beiiig in the form of spiral elements for advancing:

the'comminuted material duringthe rela-- tive movement of said tivo sets of electrodes 9. An electric furnace for the treatment of comminuted material, comprisinga container, a plurality of outer electrodes supported on the inner .surface of said container, a shaft passing through said container, a plurality of inner electrodes car'- ried'by said shaft, and means for rotating said container. and the outer electrodes carried thereby, and said shaft, and the inner electrodes carried thereby, in oppositedi'- rections, to thus bring about a relative rotation of said outer and inner electrodes.

l0. An electric furnace for the treatment of comminuted material, comprising a container, a plurality of outer electrodes supported on the inner surface of said container, a shaft passing throughrsaid con'- tainer, a plurality of innerelectrodescarried by' said'shaft, and means for effecting a relative rotation of said outer and inner electrodes, the electrodes of said set of outer electrodes being in` the' form' of spiral elements' for advancing the comminuted ma-v terial Vduring the relative rotation of said two sets of electrodes. Y

1l. An electric furnace for the treatment of comminuted material, comprising a container, a plurality of outer electrodes supported on the inner surface of said container, a shaft passing through said container, a plurality of inner electrodes carried by said shaft, and means for rotating'said container and the outer electrodes carried thereby to thus bring about a relative rotation of said outerand inner electrodes, the outer electrodes being formed to advance the comminuted-material during tlierelative rotation of said two sets of electrodes. 1

12. An electric furnace'for the treatment of comminuted material, comprising a oon-Y tainer, a plurality'of Vouter electrodes supported Aon the inner surface of said container, a shaftpassing through said container, a plurality of inner electrodes carried by saidv shaft, and means for rotating said container, and the outer electrodes carried thereby, and said shaft, and the inner electrodes carried thereby, in opposite directions, to thus bring about a relative rotation of said-outer and inner electrodes, the `electrodes of said set of outer electrodes being in the form of spiral elements for advancing the-comminuted material during the relative rotation of Vsaid tivo sets of electro-des.

18. In an electric furnace for the treatment of comminute'd material, a heating chamber, and-a plurality of electrodes Within said chamber, said electrodes being inthe form of spiralelements soas to eect an advance of said material Within said chamber, and means for effecting a relative movement of said electrodes with respect to said material.

111. ln an electric furnace for the treatment of, comminuted material, a heat-ing chamber, and a plurality of electrodes carried by the inner Wall of said chamber and being shaped to effect an advance of said material Within said chamber, and means for effecting a relative movement of said electrodes with respect to said material.

15. ln an electric furnace for the treatment of comminnted material, a. heating chamber, and a plurality of electrodes carried by the inner Wall of' said chamber, said electrodes being in the form of spiral elements so as to effect an advance of said material Within said chamber. and means for effecting a relative movement of said electrodes with respect to said material.

16. An electric furnace for the treatment of comminuted material, comprising a heating chamber, a plurality of electrodes Within the same, and feeding means secured to the inner Wall of said chamber for eecting an advance of said material.

17. An electric furnace for the treatment of comminuted material, comprising a heating' chamber, a plurality of agitating electrodes Within the same and rotatable independently of said chamber, means for effecting a relative movement of said electrodes BEST AvAiLAeLE coe 5 with respect to said material, and means independent of said electrodes and secured to the inner Wall of said chamber for effecting an advance of said material.

18. ln an electric furnace for the treatment of comminuted material. a heating chamber, and an electrode Within said chamber, said electrode being in the form of a spiral element so as to eect an advance of said material Wit-hin said chamber upon the relative movement of said electrode With respect to said material.

19. ln an electric furnace for the treatment of comminuted material; a heating chamber, and an electrode carried by the inner Wall of said chamber and being shaped to effect an advance of said material vvithin said chamber upon the relative movement of said electrode with respect to said material.

20. In an electric furnace for the treatment of comminuted material, a heating chamber, and an electrode carried by the inner Wall or" said chamber, said electrode being in the form of a spiral element so as to effect an advance of said material Within said chamber upon the relative movement of said electrode With respect to said material.

In testimony, whereof, I have signed my name to this specification this th day of lslarch, 1923.

JOHN J. NAUGLE. 

